“A failure in rolling over the maturing Lebac stock would lead to a disorder bid on the dollar and renovated capital outflow,” JPMorgan analysts Diego Pereira and Lucila Barbeito wrote in a note last week.

Speculators have been selling en masse as Central Bank Governor Federico Sturzenegger gobbles up everything that comes his way. Tuesday’s sale will be closely watched.

DOLLAR

On Monday, Banco Nación had a buying rate of 24.50 pesos and a selling rate of 25.50, for a 7.4 percent increase on rates at close of business last Friday.

The peso has lost 30 percent of its value since the start of the year.